As it is generally known, in the area of computer programs, many specific types of data storage and retrieval systems are currently available. For example, a database is a collection of information that is organized so that it can be conveniently accessed, managed, and updated. Databases are sometimes classified according to their organizational approach. The most prevalent approach is the relational database, a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways. A distributed database is one that can be dispersed or replicated among different points in a network. An object-oriented programming database is one that is congruent with the data defined in object classes and subclasses. Other specific types of databases are also available. A database manager often provides computer system users with the ability to control read/write access, specify report generation, and analyze usage. SQL (Structured Query Language) is an example of a standard language for making interactive queries from and updating a database.
In any specific type of data storage and retrieval system, it may sometimes be desirable to organize data items into categories. It may further be desirable that such categories be associated with category definitions of some kind or type. If information items are appropriately organized based on such definitions, system performance may be improved by such techniques as indexing of the information items, to provide search index data structures that improve the performance of search operations. However, due to their specific nature, not all categories of information items may be considered closed ended for purposes of definition, and therefore are not amenable to static category definitions.
For example, where there may be a need to provide category definitions for information item categories such as those representing or associated with appointments ranging over specific time periods. Such a situation may arise when categories would be helpful in determining appointment information items associated with any specific day, week, month, year, or other period of time. However, it may not be feasible to provide an exhaustive set of category definitions corresponding to all possible time periods. A solution in which discrete category definitions are established and maintained for every possible interval of time would result in an excessively high number of appointment categories. Alternatively, a limited number of such static category definitions may result in a system that is overly restrictive with respect to determining and/or collecting appointment information.
For the above reasons and others, it would be desirable to have a new system for information item categorization that does not rely on exhaustively defining all possible categories that may be needed. The new system should further allow for category definitions that can advantageously be used to provide improved system performance, such as through effective and efficient indexing of information items with regard to the category definitions.